/**
 * InvalidHmacError is thrown when HMACs don't match
 * @source https://rclayton.silvrback.com/custom-errors-in-node-js
 */
export declare class InvalidHmacError extends Error {
    constructor(message?: any);
}
/**
 * Generate a new TWT from a payload and signature
 * @param payload - Payload
 * @param secret - Secret
 * @example
 * // returns "hello5112055c05f944f85755efc5cd8970e194e9f45b"
 * sign("hello", "secret");
 */
export declare const sign: (payload: string, secret: string, length?: number, algorithm?: string) => string;
/**
 * Verify a TWT using its secret
 * @param twt - TWT
 * @param secret - Secret
 * @example
 * // returns "hello"
 * verify("hello5112055c05f944f85755efc5cd8970e194e9f45b", "secret");
 * @example
 * // Throws an InvalidHmacError
 * verify("hello-this-is-not-the-correct-hmac", "secret");
 * @example
 * // Throws an InvalidHmacError
 * verify("hello5112055c05f944f85755efc5cd8970e194e9f45b", "incorrect-secret");
 */
export declare const verify: (twt: string, secret: string, length?: number, algorithm?: string) => string;
/**
 * Decode a TWT **without** verifying it (not recommended)
 * @param twt - TWT
 * @example
 * // returns "hello"
 * decode("hello5112055c05f944f85755efc5cd8970e194e9f45b");
 * @example
 * // returns "hello"
 * decode("hellothis-is-not-the-correct-hmac");
 */
export declare const decode: (twt: string, length?: number) => string;
/**
 * Validate a TWT **without** verifying it
 * @param twt - TWT
 * @example
 * // returns true
 * decode("hello5112055c05f944f85755efc5cd8970e194e9f45b");
 * @example
 * // returns false
 * decode("hellothis-is-not-32-characters");
 * // returns true
 * decode("hellothis-is-32-characters-abcdefghijklmnopqr");
 */
export declare const validate: (twt: string, length?: number) => boolean;